Purpose: This study is a Phase I study designed to test the safety of the 10% IVIG chromatography processed product. Methods: The blinded study is six month crossover with subjects receiving three months of Gamimune-N 10% then three months of the 10% chromatography preparation. Investigators are blinded to the order of administration. It is a multi-center study. Results: At this site 4 patients are enrolled. All patients have crossed over to the second product. Infusions have been tolerated very well. In the 19 infusions to date, there has been one episode of shortness of breath and wheezing during the infusion. This was managed by a temporary decrease in the infusion rate and the administration of albuterol via metered dose inhaler. The patient was able to complete the infusion without further reaction. Laboratory studies have been performed as outlined in the protocol. Results of note are for patient #1. On two immediate post-infusion and 24 hour studies there was a conversion to positive Coombs test. On a one week follow-up study the test had converted back to negative Coombs test. The mechanism for this reaction is thought to be antibody mediated. The significance of these reactions is unknown. Similar reactions have occurred in patients at other sites. All patients have converted back to Coombs negative by one week post- infusion. There was no clinical or laboratory evidence of hemolysis and all patients have remained on the study. Because the study involves blinded randomization to IGIV-C or IGIV-S/D, it is not known which product(s) is/are associated with the positive Coombs result. Significance: Development of safe intravenous gammaglobulin preparations is necessary given the current shortage of product. This productg contains processing steps designed to prevent spread of viral pathogens. Future plans. This study is scheduled to be followed-up with a Phase II study scheduled to begin mid-year 1999. The protocol for the Phase II study is under development.